Laser catheters and laser delivery systems in general have wide range of applications in the medical field. Such systems may be used to deliver laser energy to desired sites of a patient's anatomy, and may be particularly suitable for delivering laser energy to locations within a patient's body that allow for minimally invasive treatment of a variety of indications using a variety of treatment modalities. Examples of some laser treatment modalities include heating tissue, stimulating tissue, drug activation within a patient's tissue and ablation of tissue.
Laser catheters currently approved for ablating and clearing blockages in human arteries may use a large single optical fiber, but may more commonly use a bundle of multiple optical fibers having a silica core, or a core of some other solid transmissive material. Large single fibers tend to be very stiff and contraindicated for use in tortuous anatomy and bundles of multiple fibers tend to lack ablation efficiency at the distal tip due to the gaps between adjacent fibers. This is particularly true for laser catheter systems that cut on contact. In addition, some indications for recanalization of blockages are particularly difficult to treat such that long term patency is maintained within a treated vessel that has been opened. This is often the case where blockages in veins present soft grumous type plaque lesions that often also include a large amount of soft thrombus.
What has been needed are fluid core waveguide based ablation catheters that are small and flexible enough to navigate a patient's vasculature, use biocompatible fluids, and are economical to manufacture. What has also been needed are such fluid core waveguide based ablation catheters that can be efficiently packaged and sterilized and maintain clinical integrity during a useful shelf life after shipment to an end user. What has also been needed are systems and methods suitable for treating grumous type lesions that improve long term patency of treated vessels.